The invention further relates to a method of giving guidance information to a driver of a vehicle, the method comprising the steps of:
Such a navigation system and method are known from U.S. Pat. No. 5,095,532. The known system receives traffic messages according to the Radio Data System (RDS). In RDS, the message is broadcast together with the audio signals of a radio program and the RDS receiver in the vehicle is equipped to receive the combined signals and to separate the message from the audio. The traffic message comprises an event, describing the particular circumstances to which the message relates, and a location, indicating the position on the road where the event takes place. In the known system, the driver inputs the route that he plans to follow during a trip and the system stores this route. When a message has been received, the known system determines whether this received message concerns a location on the planned route. If this is the case, then the message is further processed and its content is presented to the driver. This filtering is employed to reduce the potentially high number of traffic messages so as to not overwhelm the driver with traffic messages. A disadvantage of the known system is that it is necessary to input and store the planned route. Furthermore, the filtering of traffic messages in the known system has a problem in that traffic messages not directly related to the planned route are discarded by the system.
It is an object of the invention to provide a navigation system of the kind set forth with an improved filtering of traffic messages. This object is achieved according to the invention in a navigation system that is characterised in that the filter module is operative: